With Google's purchase of Frommer's from John Wiley & Sons, it may be time to retire the trope. The travel-guide publisher is indisputably a content business, not a platform or a network or anything else more quintessentially Google-y. It hires writers to write books about places to visit, and publishes professionally-written articles on its website, where it sells ads against them.

Whether or not Google merges the two brands, as it's reportedly considering, the obvious guess is that Google will Zagat-ize Frommer's, de-emphasizing professionally-produced content in favor of user-gen stuff, which is both cheaper to produce and more in keeping with its traditional competencies. For the moment, however, Google is, at least in a small way, unarguably a media company.

And that means it's time once again to ask the question inevitably posed in every "Is Google a media company?" article: How long can Google be a fair arbiter of all the world's information when it increasingly has information of its own that it wants to promote?